| US 7,513,440 B2 | ||
| Pressure-boosted fuel injection device comprising an internal control line | ||
| Hans-Christoph Magel, Pfullingen (Germany) | ||
| Assigned to Robert Bosch GmbH, Stuttgart (Germany) | ||
| Appl. No. 10/531,166 PCT Filed Oct. 07, 2003, PCT No. PCT/DE03/03314 § 371(c)(1), (2), (4) Date Apr. 11, 2005, PCT Pub. No. WO2004/036027, PCT Pub. Date Apr. 29, 2004. |
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| Claims priority of application No. 102 47 903 (DE), filed on Oct. 14, 2002. | ||
| Prior Publication US 2006/0043209 A1, Mar. 02, 2006 | ||
| Int. Cl. F02M 47/02 (2006.01) | ||
| U.S. Cl. 239—88 [239/96; 239/124; 239/533.9] | 11 Claims |
| 1. A fuel injection device (1) adapted to be connected to a high-pressure source (2), said fuel injection device (1) comprising:
a multi-part injector body (4; 8, 9, 10);
an injection valve clement (24) in said multi-part injector body for blocking or unblocking at least one injection opening (25);
a nozzle chamber (23) enclosing the injection valve element in the region of a pressure shoulder provided on the injection valve element (24);
a pressure booster (11) provided in said multi-part injector body, said pressure booster (11) comprising a pressure booster piston (14), a working chamber (12) on one side of said piston and a differential pressure chamber (17) on an opposite side of said pressure booster piston, said pressure booster piston (14) sealing the working chamber (12) off from the differential pressure chamber (17), said pressure booster piston (14) being actuated by means of a pressure change in said differential pressure chamber (17), a high-pressure chamber (19) defined, at least in part, by an end face (14a) of the pressure boosting a piston (14);
a nozzle chamber inlet (22) hydraulically connecting the nozzle chamber (23) with the high-pressure chamber (19);
a control chamber (20) hydraulically connected to the high-pressure chamber (19);
an on-off valve (5, 70) for actuating said fuel injection device (1);
a central control line (31) extending through said pressure booster piston (14), said pressure change in the differential pressure chamber (17) of the pressure booster (11) occurring via the central control line (31); and
wherein the central control line (31) extends essentially coaxially to an axis of symmetry of the pressure booster piston (14),
wherein the central control line (31) extends through the working chamber (12) of the pressure booster (11) and further comprising a high-pressure-tight connection (33, 50, 61) for sealing off said central control line (31) from said working chamber (12).
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